Call Flow Summary - Cisco ASR 5000 Series Administration Manual

▀ Call Flow Summary

Call Flow Summary
Important:
common or likely commands and/or keyword options are presented. In many cases, other optional commands and/or
keyword options are available. Refer to the Command Line Interface Reference for complete information regarding all
commands.
The following steps describe the call flow as regards the timers that affect a call initiated by the Mobile Node (MN).
1. The call arrives at the system and A11 (or L2TP, for Closed RP interfaces) (or L2TP, for Closed RP interfaces)
is processed successfully. The call arrives at the system and R6 isThe call arrives at the system and R6 is
processed successfully. The GGSN receives a Create PDP Context Request MessageThe GGSN receives a
Create PDP Context Request Message from the SGSN. The call arrives at the system, the subscriberThe call
arrives at the system, the subscriber is authenticated, and an IPSec SA is established.
2. Based on the subscriber profile retrieved from AAA server or the subscriber profile configured locally in the
authentication context or the default subscriber profile configured, it is determined whether this call is a Simple
IP or Mobile IP call. A subscriber profile retrieved from AAA always takes precedence over the values locally
configured for that subscriber or the default subscriber. This is true for timer settings including IDLE and
ABSOULUTE timer.PPP negotiation is started. At this point,PPP negotiation is started. At this point,PPP
negotiation is started. At this point, since authentication is not performed the system does not have a username
or password. So during the PPP phase, the system selects the default subscriber in the source context for a
subscriber template (DNS, and timer settings can be configured in the default subscriber template). Once PPP
is successfully established the system understands that the call is a Mobile IP call. since authentication is not
performed the system does not have a username or password. So during the PPP phase, the system selects the
default subscriber in the source context for a subscriber template (DNS, and timer settings can be configured in
the default subscriber template). Once PPP is successfully established the system understands that the call is a
Mobile IP call.The system determines the propertiesThe system determines the propertiesThe system
determines the properties to apply to the call from the APN template used. The APN provides such information
as the authentication and accounting methods, and whether or not to use Mobile IP.
3. The system determines which FA service to use for communication with the HA service based on the PDIF
service configuration.
4. The system still does not know the username and password at this point, so it looks at the default APN template
for 3GPP technology subscribers and subscriber profile for other technology subscribers. If the idle or absolute
timeouts are configured, the system compares the settings for the idle and absolute timeout to the setting for the
advertised registration lifetime in the FA-service.
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▄ Cisco ASR 5000 Series Gateway GPRS Support Node Administration Guide
Commands used in the examples in this section provide base functionality to the extent that the most
Use the following example to set absolute and idle timeout for the default subscriber in non-3GPP
network:
Mobile-IP and Proxy-MIP Timer Considerations
OL-22944-02